Like other ships, a submarine can float because the weight of the water that it displaces is equal to the weight of the ship. This means the pressure of the submarine pressing down on the water is the same as the pressure of the water pushing up on the ship.

A submarine is different from other ships, though, because it can control its buoyancy. This means the submarine captain can decide when to sink down into the ocean or come back up to the surface.

In order to control buoyancy, the submarine relies on special tanks that can be filled with water or air. To return to the surface, the tanks are filled with air. This makes the submarine less dense than the water around it, causing the sub to float to the surface.

When the captain decides it's time to take a dive, the air is released through a vent, and the tanks are flooded with water. This makes the submarine denser than the surrounding water, which causes it to sink.

A supply of air is kept on board to fill and refill the tanks. In an emergency, the tanks can be filled with high-pressure air to return the crew and the vessel to the surface very quickly.

Living on a submarine might sound like fun, but there are challenges to life under the sea. The three biggest problems involve maintaining air quality, fresh water supply, and temperature.

Imagine you are about to be sealed in a giant tube with all your friends. When the tube is sealed, all the air available to you is now inside. There's just one problem: no air can get in or out. A submarine works the same way.

In order to keep people breathing (and alive!), three things must happen. First, oxygen must be pumped into the vessel as the crew uses it up by breathing. Oxygen is typically supplied to the submarine from pressurized tanks. A computerized system monitors oxygen in the air and releases fresh oxygen as its needed by the crew.

Finally, exhaled moisture from breathing must be removed to prevent condensation on the interior of the ship or equipment. This is done with dehumidifiers.

As you know, humans can't live long without water. Since submarines don't have access to municipal water systems or wells, they have to find a way to maintain a fresh water supply for drinking.

Most ships have special equipment that can remove the salts from seawater to turn it into fresh drinking water. This process is called distillation. Some submarines can produce up to 40,000 gallons of fresh water per day. It is used for everything from cooling electronic equipment to cooking and showering.

Since submarines are metal, they conduct heat from inside the ship to the cooler surrounding water. In order to keep the crew comfortable, submarines also need heating systems.

Did you get it?

Wonder What's Next?

Try It Out

Ready to dive even deeper to learn more about submarines? Enlist a crew of friends or family members to help you explore the depths of the following activities:

Would you want to spend several months in a submarine at the bottom of the sea? Why or why not? Imagine what life would be like if you were confined to a submarine for an entire summer. What would you miss? What would be fun about it? Make a list of pros and cons and share it with a friend or family member. Do they feel the same way as you do? What pros and cons can they think of?

It may not be able to take you to the bottom of the ocean floor, but this homemade ship will put you in control of your very own submarine. So what are you waiting for? Are you ready to head down under, captain?

Does water really exert force on submerged things? You bet it does! To learn more about this force, check out The Pressure of Water experiment. All you'll need is your hands and a plastic baggie. Share what you learn with friends and family members!

Wonderopolis

ms.chesser

Malcolm

Apr 27, 2017

The first submarine ever made is debatable because the definition of one is. However, it is a well known fact that the first combat victory by a submarine was the sinking of a blockading union gunship by a confederate Davis class submarine. The boat had a mine on a pole in front of it and it rammed the mine into the gunship, the sub was sunk in the ensuing blast. The first modern submarine was commissioned in 1900 after a long feud between it's inventor, John p. Holland (the sub was called the Holland class) and the navy. The sub was armed with two torpedo tubes with whitehead torpedoes. The Holland class was never used in anger. During WW1, submarines were used, first by the Germans, to sink ships using the element of surprise.

sebastian

Wonderopolis

Jan 21, 2016

Thanks for asking, sebastian! You may use Wonderopolis as the author and since we do not list the publish date, you can use the date you accessed the article for information. If that was today, then use today's date for your citation. We're glad you're WONDERing with us! :)

ball is life

Wonderopolis

Sep 27, 2015

That's a WONDERful question, WONDER Friend! Many times they are released off a large ship. However, we encourage you to keep researching this question to learn more. We would love to hear about what you find out. Keep up the GREAT WONDERing! :)

John from England

Wonderopolis

Apr 8, 2015

We're sorry you did not like this WONDER, John from England! Did you know there are over 1,400 WONDERS to explore and more than 100 categories? There is also a new WONDER of the Day every weekday! We are sure you can find something that interests you here on WONDERopolis. We hope you will check out the other WONDERS and keep WONDERing with us! :)

dasean campbell

Wonderopolis

Feb 24, 2015

Welcome, dasean campbell! Submarines are sometimes used in war situations. You could do more research on submarines at your library. Here is another WONDER about submarines - Wonder #624: How Does a Submarine See Above Water?. Always keep WONDERing! :)

Charlie

Jun 12, 2014

This article was a very clear explanation for how a submarine works and I liked how they explained how buoyant force works. I never knew it was so complicated. But I have one question, how does the captain control the submarine with his crew?

raymond

Wonderopolis

Mar 15, 2014

Great Question, Raymond! The Navy does operate a lot of submarines. Also, submarines are used a lot for tourism purposes. Did you know that you could ride in a submarine? Cool, huh? Thanks for WONDERing with us, Wonder Friend! :-)

ashiyah

Wonderopolis

Mar 12, 2014

We agree, Ashiyah! Going down deep under water in a submarine can be very scary. We are glad that we now know the science behind it all. That makes us feel better about giving it a try. Thanks, for WONDERing with us today! :-)

Reico from Mrs.Bahler's Class

Wonderopolis

Mar 11, 2014

Great question, Reico! Thanks to the Internet, we can travel and have lots of experiences! We can even take a trip on a submarine! We are glad that you joined us today! We hope you enjoyed your experience! Thanks for WONDERing with us today, Wonder Friend! :-)

xavier from Mrs. Bahelr's Clas...

Wonderopolis

Mar 11, 2014

That's a great question, Xavier! You may want to check out the Wonder Video from Wonder #213: What Does a Barometer Measure? This Wonder may help to explain air pressure. Now, just think about the pressure that water can put on an object. Thanks for WONDERing with us today! :-)

Asia from Mrs. Bahler's Class

Wonderopolis

Mar 11, 2014

That's a great question, Asia! We think it depends on where the submarine is located and the time of day it is. Some water looks bluer and can reflect the Sun's light better. Thanks for WONDERing with us today! :-)

Maddie

Wonderopolis

Mar 11, 2014

Great question, Maddie!
Newsreels were popular at the beginning of the 20th Century, when people didn't have computers or TVs. People would go to public places like theaters to find out what was happening in the world. These film reels with the news on them were known as newsreels.
We think this would be a WONDERful question for a Wonder of the Day! Be sure to submit your questions under the "What Are You Wondering" section, so that your friends can Vote for your Wonder! Keep WONDERing! :-)

Ms. Tesa's Class

Mar 11, 2014

We are still WONDERing:
- What happens when a sea animal attacks?
- How much gold can submarines hold?
- What it is the longest submarine in the world?
- Where do they store oxygen on a submarine?
- How deep can a submarine go?

Wonderopolis

Mar 11, 2014

Hello, Ms. Tesa’s Class! It sounds like you all are ready for an adventure into the deep blue sea! We think that is WONDERful! Did you know that the actual information for how deep a submarine can go is classified by the Navy. That means they don't want to public to know just how deep their submarines can go. However, we know it has to be more that 800 feet. Great questions! Thanks for WONDERing with us today, Wonder Friends! :-)